APET and PETG Differences?

sheet and profile related discussions

Moderator: Louis

APET and PETG Differences?

Postby Adee on Thu Jun 19, 2008 4:29 am

Since PETG means glycol modified PET where we add 20-30% of Cyclohexanedimethanol to totally retard crystallization thus making PET essentially uncrystallizable or amorphous. So whats the difference between PETG and APET?

Does APET have the ability to crystallize? and what is the composition of APET?
Adee
 
Posts: 15
Joined: Thu Jun 19, 2008 4:22 am

Re: APET and PETG Differences?

Postby Tom on Thu Jun 19, 2008 8:58 am

PET can be amorphous or semi-crystalline. When in the amorphous state is is sometimes called APET.

PET crystallizes slowly. Thick section are often hot enough, for long enough, to allow for some crystals for form. This is undesireable in most PET processes.

PETG is more expensive. So most will use PET when they can, which is one reason why PET greatly outsells PETG.
Tom Cunningham

Extrusion Technology and Consulting

http://www.ExtrusionTechnicalServices.com
Tom
 
Posts: 501
Joined: Wed Aug 29, 2001 12:00 am

Re: APET and PETG Differences?

Postby Adee on Thu Jun 19, 2008 10:56 pm

Thanks Tom.

so correct me if I am wrong

APET = Just Amorphous state of PET resin (it can be crystallized)

PETG = Glycol Modified giving PET more impact strength than conventional homopolymer PET. (if CHDM is over 30% then PET wont even crystallize at 170C and would remain amorphous kinda like Polystyrene)

CPET = Crystallizable PET doped with Nucleating agents and impact modifiers and its purpose is to make heat resistant ovenable/microwavable trays

BoPET = Bi-axially Oriented PET film which is stretched bi-axially under heat and stress and then either thermosetted (Crosslinked) or crystallized to stop it from being pulled back to its original shape

RPET = Recycled PET (self explanatory)

Am I Correct? or am I missing some PET categoty?

Thanks again for help
Adee
 
Posts: 15
Joined: Thu Jun 19, 2008 4:22 am

Re: APET and PETG Differences?

Postby Tom on Fri Jun 20, 2008 7:21 am

I don't think there is a standard naming convention. Don't expect that you can use these acronyms and have everyone understand exactly what you are specifying.
Tom Cunningham

Extrusion Technology and Consulting

http://www.ExtrusionTechnicalServices.com
Tom
 
Posts: 501
Joined: Wed Aug 29, 2001 12:00 am

Re: APET and PETG Differences?

Postby Adee on Mon Jun 23, 2008 12:04 am

yea I guess you are right!!

The reason I was interested in it was because resin manufacturers often times sell their PET as APET, CPET, PETG etc. The reason they probably do that is because the customer would know their end use immediately. So, I always wondered what would be the difference between them chemically. But I think you are correct that there is no standard way to catagorize this.
Adee
 
Posts: 15
Joined: Thu Jun 19, 2008 4:22 am


Return to Extrusion

Who is online

Users browsing this forum: Google [Bot] and 3 guests

cron